Music was iconic, SML sung that song at his wedding afaik.

On SFL, my opinion (not sure if shared, but I would say factually correct) is that the show *did* kind of shy away from the wreckage she left behind her, for example by not showing flashbacks of HS bearing with her lies for more than a year, or imagining her with her lover, etc. This was all mentioned, but then it was either dropped or brushed aside, so it was:
1. Kind of brought up in single occasions and then not mentioned again
2. Ignored as if phychological trauma and emotional damage simply disappeared when convenient, as if by choice, like one could flip a switch rather than go to therapy
3. Minimized, or muted/dampened reactions compared to the true pain and emotional damage and wreckage that going through such experiences would have caused, which is why I never suspected a betrayal until he brought it up at the airport... I would say, for example, that his adverse reaction to DK was tamed even if you consider he played it cool while being hurt and disturbed, but it was I would say not even, or barely, the level of insecurity one would feel for her running away with the guy, not what I would expect if she had actually been seeing him behind his back for more than a year prior to running off with him. Also him meeting the guy and shaking hands, and putting up that atrocious conversation about a project with the guy that couldn't even remember how many time he had met him, as if everything was okay.

I would also say definitively that she wasn't really willing to face such damage and was not even asked to, and in fact did not, despite her wanting to have another chance with Han-sung. When he unloaded the pain he felt at knowing and putting up with her more than year long daily lies when she told him she was working while meeting DK behind his back, and then run off ignoring his pleas and begging for her to stay, she brushes it aside and absurdly assumes that now that he had could be with her after all that pain and effort (on his part) he should not even think about feeling love for anyone else... Can one get more delusional than someone that assumes that humiliating and deceiving your partner for more than a year, then running of with your lover for two without a single word, makes for someone that one would want to have around? Anyone sane would have told her that he would leave the "honor" and "privilege" of dating her to someone else, and the true question is not how he could love someone else, but how couldn't he love anyone else (including nobody, i.e. staying single). Not that this is ever discussed again in any serious manner, it's brought up in a creepy fashion at the end where HS is made to listen to her minimize and brush aside flippantly this horrific betrayal and try to compare it with his onesided and short lived mini-crush and unreciprocated little kiss, which is about as serious a comparison as one's pimple and Mt. Everest. One then wonders why he didn't open up about his insecurities about DK, who he understandable hates, as he says, and played it cool while not being okay, something she knew and exploited -mentioning their NY home in front of him, trying to make him jealous with a man she cheated with for more than a year, and telling him DK loves her still and she might be starting to feel the same when she threatened going to NY... is this the behavior of someone that cares about their partner's psychological health and emotional well being or of someone that is self centered and doesn't put any weight in the (impossible) task or rebuilding trust (not that she is ever asked to, it's an issue that by magic does not make an appearance, again the consequences of her actions being brought up only when convenient for the plot). Making a joke out of his insecurities with DK and her betrayal after witnessing his emotional breakdown at the side of the road to the airport? And listening to that and still being concerned only with what she felt, daring to talk about feeling pathetic when he confessed to having lived through the hell of knowing of her betrayal for more than a year, forgiving her and begging her to stay, only to be left when she run off with her lover and he didn't hear from her again for two years? How self absorbed and utterly shameless do you need to be to prioritize yourself?

I don't know if this would be considered a wicked woman trope, to be honest none of the characters were flat, but she as sure as anything is true was toxic in the extreme, I would say even up until the end we have her talking about wanting to escape the damaged pride of having HS leave her by running away first (and therefore lying about it being about giving him a choice -she was strong arming him and not giving him space, after he was willing to wait for her for years -not that he should have, he should have tried to move past it, given that despite the delusion of imagining some mystical connection, the reality of the situation is that she had been lying to his face for more than a year and then run off, and only came back after she and DK broke up, which absolutely nothing guaranteed would happen... and if you think someone would never stab you in the back and then deceive you for more than a year, maybe it's time to consider that you don't know them as well as you think you did, and the person worthy of such loyalty, respect, honesty and trust existed only in his head, while the real person did not deserve any of those things, having shown herself to be disloyal and untrustworthy. One would reevaluate their judgment (and in the case of anyone sane with a shred of love and respect and self dignity, conclude that they didn't deserve him, or his loyalty, respect and trust, having shown him none of the former two and broken the latter -his trust-.

I wouldn't really say the show treated every character with mercy and understanding and nuance, I really felt that HS's insecurities and trauma was swept under the rug, I would have liked much more focus on the more than year long deception and the whole background: she said she loved DK. Did she not love HS? And now she loves him again? And doesn't love DK? What happened? How did it come about? Can they please address her betrayal without making a joke about it (and forcing HS to go along with the joke the same way they were joking about HS and FL, namely not really a joke)? And maybe his insecurities around DK, without him feeling unable to open up and having to play it cool, with her mocking him when she knew about how he felt towards the guy and still teased him, talked to him on the phone and had one on one meetings and lunch with the guy, and used him, the person she had been betraying HS with for more than a year and run off with for two more, to make HS jealous, something that appears insanely cruel. I mean, think about the pain when he brought up the more than year long string of lies she told to his face on the side road on the way to the airport, which she brushed aside in the most insulting way possible, and with the most revolting moral equivalence -really, more than one year of hell where she cheats on someone that would never even take coffee with another girl, and for which she was his whole world and would have never thought her capable of such a betrayal, followed by running off with her lover to another continent without a word for two years, talked about in the same phrase as a one sided mini-crush with a small unreciprocated kiss? Messages with someone that rejected him that he read on the side? When she is someone that deceived him in such a manner for more than a year, and shows no respect or consideration for his perspective, minimizing and making a joke out of his understandable insecurities, flirting and meeting up with someone she cheated on HS with for more than a year, and that still has feelings for her (and is creepily ambiguous and touchy feely, the intimate head caress taking on a whole other feeling after her betrayal and considering that, contrary to the cousin who put his head on her lap, DK did get between her and HS). Nothing about this is her taking responsibility in any mature sense, or in any sense of the word at all, in fact she merely showed up after more than a year of lies and two years where he didn't heard from her and knew of her through the press, and he basically took her back immediately. None of the issues are discussed after being brought up, his insecurities and the betrayal are made into a joke, rather than taken seriously and actually addressed, and she does absolutely nothing to gain his trust back (or not lose it further, for example by meeting up with a still smitten man who she cheated on HS with while not only fully knowing his insecurities after she had completely destroyed his trust, but even exploiting these insecurities to make him jealous, throwing DK's love in his face and telling him she might be loving him back again, and threatening to leave, despite his pleading, rather than giving him space -in the end, she doesn't give him space, it's him that is reduced to begging and then she comes back after going missing without saying anything-). Not that I think in real life it would be possible for her to rebuild said trust, but it's interesting to note that she does not even try, and the show basically brushes everything aside and she is taken back immediately, her using a men she cheated with to coerce HS into begging her not to leave turns into mocking his insecurities around DK, and talking about wounded pride (one of, but certainly not the main reason he would not want to hear his name, and more than enough to make his blood boil, given the more than year long betrayal, her callousness and lack of consideration in talking with him on the phone and meeting up one on one, having lunch together, and explicitly making use of him to make him jealous, without any consideration for how he might have felt, despite playing it cool, after she had lied to him for more than a year and run off for two... again, the threat makes it clear she knew exactly what buttons to push, and the flirting with the cousin might not be threatening because he doesn't have a chance -but still inconsiderate all things considered for her not to put down boundaries-, but the intimate interaction with DK, not putting down strong boundaries as he tried to flirt with her, but rather cleverly retorting while meeting up together to reminish about their first meeting, him touching her head intimately, etc., while he was the man she cheated on HS with, and she is supposed to try to make an attempt to heal the emotional wounds, rebuild trust, address his insecurities with care, concern and respect for his point of view -not necessarily agreeing, but at least taking it seriously and not turning it into a joke-... she is doing the opposite of that, not that imho in reality she would have a chance to rebuild trust even if she tried, but the show does not even require her to, she is taken back and he is the one begging her not to leave a second time, kimtchi takes up more time than working through the betrayal).

Bottom line, she barely apologizes, contrary to My Mister the actual consequences of the betrayal are not really shown -to the point that until the episode with the breakdown at the side of the road to the airport I was convinced she had simply left him, not lied to him for more than a year, which has totally different implications... dumping him would have been a choice that treated him with respect and honesty if she didn't love him, and loved DK, given that the alternative was doing what she did, namely humiliating and deceiving him for more than a year are quite another matter-. My Mister talks about how dramas romanticize or minimize affairs, and in this case we conveniently are not shown flashbacks of the pair of discovering the betrayal, or thinking about her with her lover behind his back, etc., we are only shown, impossibly, happy memories, which given his outburst in the beginning and at the side of the road were not the only thing on his mind... but if we were show it, then we would be forced to face reality and wonder why would anyone with a shred of self respect and self dignity pine after someone like that or want to take her back, same reason, I guess (in addition to shock value) to make it clear that she actually was lying about working and seeing DK behind his back for more than a year so late in the game, increasing the chances that the viewer is already committed to the pairing (in fact the betrayal is not brought up in a serious manner ever again, despite the obvious pain HS felt when he brought it up, and it being a raw issue that would realistically have needed to be discussed together with the DK elephant in the room, and her using his pain at her betrayal to make him jealous, weaponizing the wound she had inflicted in a sociopathically cruel and sadistic fashion. Again, good thing that at least she was jealous (the reason she did this) because at least she cared, then again when she talked about the pride of not letting him leave her, when he was begging her to stay after more of a year of lies back in the day, and is now begging her again after her repulsive ultimatum and power play on his emotional wounds tied to DK, threatening to leave him for DK, or when she mentioned feeling pathetic when he watched messages (platonic ones) from FL after hearing him confess the heartbreak of more than a year of her lying to his face and abandoning him among his pleas, not to be heard from for two years... I mean, does she have any shame, any sense of perspective? Is it possible for her to not even acknowledge that what she is feeling is a billionth of what he had felt, than what he had done is a billionth of a fraction than what she had put him through, a hell that lasted for a long time? How could she be focused on herself and talk about this without acknowledging *his* pain, humiliation, wounded pride, broken self dignity and self respect (he resorted to begging and was ignored), broken trust... I mean, to hear this and not want to disappear in shame at the very notion of talking about yourself, given the magnitude of the difference in what she had done to him.... this is not taking responsibility in any sense of the word. The definition of toxicity.